Mangual-Crespo, Gerardo, and Franklin W. Martin. “Effect of Spacing on Seed, Protein, and Oil Production of Four Okra Varieties”. The Journal of Agriculture of the University of Puerto Rico 64, no. 4 (October 1, 1980): 450–459. Accessed April 25, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/10191.